The invention proceeds from a treatment device for material strands and a method for treating a material strand.
The publication DE 102 33 299 A1 discloses an apparatus with a lifting device and a method for receiving a material strand in the form of a plasticitate, in particular a tacky plasticitate, which lies on a conveyor belt, for transport and for depositing in the press mold of a molding press. In this case, the plasticitate is received by one or more elastic carrier plates.
If the material strand is to be cut, direct methods, as they are referred to, are known, in which continuously discharged, fiber-reinforced, tacky and limp material strands are processed directly into a molding. These material strands are mostly received and transported further on by wire mesh belts.
Cutting takes place, in the discharged state, mostly by shears, so that the tacky material strand is not pressed onto the conveyor belt. For this purpose, the transport system is divided, for example, into two transport units, so that shear parts are accommodated between the end deflection and start deflection of the two transport units.
As a rule, as mentioned, the discharge of the material strand takes place continuously and often also at variable speed. The shears for cutting are therefore co-moved with the transport units at the current discharge speed. After the cut has taken place, the shears are moved back into their initial position again, so as to be ready for the next cut. The return speed and the respective transport unit speed are set such that the uncut material strand on the front transport unit experiences only the discharge speed. After the cutting operation and before the return, the rear transport unit can transport the cut-to-length material strand away at higher speed. By the conveyor belt being subdivided by the shear gap, narrow limits are placed on the limpness of the material strand, this being further intensified by its tackiness. Although this can be counteracted by means of non-stick coatings or non-stick powder on the conveyor belt, it is nevertheless still necessary to have a sufficiently high rigidity of the material strand so that it can overcome the gap. On the other hand, if the material strands are thick, the cut surfaces may adhere to the shear blades and prevent fault-free production.
The object on which the invention is based is, in particular, to provide a treatment apparatus for material strands and a method for treating material strands, by means of which an improved handling of limp, thin and tacky material strands can take place.
This is achieved, according to the invention, by means of the features of the independent claims. Further refinements may be gathered from the subclaims.